Folding box blank feeding and folding devices



1961 c. J. PIERCE, JR 3,008,385

FOLDING BOX BLANK FEEDING AND FOLDING DEVICES Filed March 21, 1-960 5Sheets-Sheet 1 INVENTOR- Cheszer .1. Pierce, Jn

BY F I 5 a z E ATTORNEY Nov. 14, 1961 c. J. PIERCE, JR 3,008,385

FOLDING BOX BLANK FEEDING AND FOLDING DEVICES 5 Sheets-Sheet 2 FiledMarch 21, 1.960

INVENTOR- Cfiesfer J Pierce, Jr.

ATTORNEY Nov. 14, 1961 Filed March 21, 1960 c. J. PIERCE, JR 3,008,385

FOLDING BOX BLANK FEEDING AND FOLDING DEVICES 5 Sheets-Sheet 5 INVENTOR.Chester .1 Pierce, Jr.

ATTORNEY Nov. 14, 1961 c. J. PIERCE, JR 3,008,385

FOLDING BOX BLANK FEEDING AND FOLDING DEVICES 5 Sheets-Sheet 4 FiledMarch 21, 1960 INVENTOR. Chesler J Pierce, Jr.

ATTORNEY Nov. 14, 1961 c. J. PIERCE, JR 3,003,385

FOLDING BOX BLANK FEEDING AND FOLDING DEVICES Filed March 21, 1960 5Sheets-Sheet 5 Z2 23 i 66 I] Fig. 9

INVENTOR- cbesfer J. Pierce, J1: W W

ATTORNEY 3,668,385 FOLDlNG BGX BLANK FEEDENG AND FOLDING DEVICES ChesterJ. Pierce, (in, Palo Alto, alif., assignor, by mesne assignments, toAtlas General Industries, Inca, a corporation of Massachusetts FiledMar. 21, 196i), Ser. No. 16,279 '7 Claims. (til. 93-5l) This inventionrelates to improvements in folding box blank feeding devices comprisingvacuum cups which remove folding box blanks, one at a time, from a blankmagazine and advance the blanks towards the portion of the machine whichshapes the box.

A preferred type of box forming machine is the plungerand-die type inwhich a plunger engages the box blank and forces it through a die.During passage of the blank into and through the die the various blankpanels are folded into the position they assume in the finished box andare then gluelessly interlocked, adhesively attached, or otherwisesecured together, so that a completed box emerges from the die.

Machines of the plunger-and-die type offer the advantage of requiringlittle floor space in relation to their capacity or output, and theinvention may be employed with advantage in machines of this type,although the invention offers similar advantages if applied to machinesin which an originally fiat blank is delivered to a conveyor inpartially folded condition for subsequent completion of the assembly atstations along the conveyor.

A blank feeder of the vacuum cup type ofiers the advantage of dependablyremoving blanks, one at a time, from the magazine and is in additioncapable of performing certain initial folding operations by forcing theflat blank partially into the die mechanism instead of depositing theblank in fiat condition above the mouth of the die. For the performanceof such initial folding operations the feeder may be fitted with a blankengaging member or members in the form of rails, edges or surfacessupporting the blank adjacent certain fold lines along which the blankis to be folded when it passes into the mouth of the die mechanism.

It is most important to maintain a high degree of accuracy in thedelivery of the blank to the die mechanism, since even small deviationsfrom the correct position may result in a misshapen box, or a box whoseglueless interlocks fail to engage properly.

In this connection it must be remembered that the high rate at whichboxes are formed does not leave time for re-centering the flat blank atthe mouth of the die between centering pins, joggers, or the like.Moreover, recentering of the blank would necessitate loss of theprefolding operations by the feeding mechanism which can ill be spared,if the box is of relatively complex construction and the plunger strokeis to be kept within reasonable limits.

Flat blanks can be stacked and held with great accuracy in the magazinefor removal from the magazine gate in a precisely defined position.However, vacuum cups are inherently non-rigid and may also permit theblank to slide slightly at the moments of pick-up and delivery.

The purpose of the invention is to maintain a high degree of accuracyduring the phases of withdrawal of the blank from the magazine,transport to the die, and insertion of the blank into the die.

A danger of shifting of the blank with respect to the feeder existsduring the removal of the blank from the magazine. Shifting may becaused when a blank offers greater-than-normal resistance to removalthrough the magazine gate, or when blanks adhere together in the stack.Shifting is further promoted by slippery, wax sized, or high gloss blanksurfaces.

assess A tendency of the blank toshift is also present when the vacuumcup grasped blank strikes the mouth of the die mechanism, particularlyin instances where the die mechanism or the blank, or both, are notsymmetrical, tending to displace the blank away from the folding elementof the die first struck by the blank.

The invention provides an improved vacuum-cup type blank feeding devicein which the position of the blank in relation to the feeder is fixedimmediately upon removal of the blank from the magazine gate. At thatmoment a sharp pointed element is forced into the blank surface toprevent any shifting of the blank relatively to the feeder. This isaccomplished by a relative motion of the blank and the pointed elementtowards each other. In a preferred manner of carrying out the inventionthe blank is retracted parallel to itself into a position in which thepoint is forced into the slightly flexed surface of the blank.

In this specification the term point is employed in a. broad sensecomprising both the point of a pin and the point of a chisel, -i.e., asharp edge.

The various objects, features and advantages of this invention willappear more fully from the detailed description which followsaccompanied by drawings showing, for the purpose of illustration, apreferred embodiment of the invention. The invention also resides incertain new and original features of construction and combination ofelements hereinafter set forth and claimed.

Although the characteristic features of the invention which are believedto be novel will be particularly pointed out in the claims appendedhereto, the invention itself, its objects and advantages, and the mannerin which it may be carried out may be better understood by referring tothe following description taken in connection with the accompanyingdrawings forming a part of it in which:

FIG. 1 is a typical box blank, the folding of which presents certaindifficulties which are successfully overcome by the invention; 1

FIG. 2 is a perspective view of a box assembled from the blank of FIG.1;

FIG. 3 is a perspective view of the magazine and die portions of afolding box assembly machine between which the blank feederincorporating the invention transports the box blanks;

FIG. 4 is a partially diagrammatic illustration of the feeder in theposition in which it removes a blank from the blank magazine;

FIG. 5 is a partially diagrammatic illustration of the feeder in theposition in which it inserts the blank into the mouth of a folding die;

FIG. 6 is a vertical cross section through a typical suction cup devicecombined with a pneumatically operated retracting mechanism;

FIG. 7 is a perspective View of the blank carrying portion of the feedermechanism;

PEG. 8 is a modified form of a portion of the mechanism of FIG. 7;

FIG. 9 is a side view, partially feeder head supporting a blankoperation; and b FIG. 10 is a side view of a preferred form of feederarm.

In the following description and in the claims various details will beidentified by specific names for convenience; The names, however, areintended to be generic in their application. Corresponding referencecharacters refer to corresponding parts in the several figures-of thedrawings.

The drawings accompanying, and forming part of, this specificationdisclose specific details of construction for the purpose of explanationof broader aspects of the invention, but it is understoodthat structuraldetails may in section, showing the during the prefolding Patented Nov.14, 1961 be modified in various respects without departure from theprinciples of the invention and that the invention may be incorporatedin other structural forms than shown.

The form of blank shown in FIG. 1 was selected to illustrate certaindifficulties encountered in the feeding and prefolding of foldingboxblanks, in that the blank is asymmetrical in the sense that greaterresistance to foldingof the front wall structure is experienced than atthe rear wall, as a result of which there is. danger of I lateraldisplacement of the blank with respect to the feeder.

The blank A of FIG. 1 consists of suitable foldable sheet material suchas paperboard and comprises a bottom panel 11 to which'side'panels 12and 13 are articulated. Dust fiaps' 14 and 15 extend from the sidepanels. A rear wall panel 16 extends from the bottom panel and has acover panel 17 articulated thereto, provided with a tuck tab 18articulated to the cover panel along a tab fold line 19. j a

A series of panels constitute a front wall assembly and comprise anouter front wall panel 20 articulated to the'bottom panel, atop wallpanel 21, an inner front wall panel 22, and a glue lap 23.

The fold line 24 along which the'top wall panel 21 is articulated to theouter front wall panel 20 comprises a slit 25 into which the tuck tab 18may be inserted in order to close the box formed from the blank A.

Lock tabs 26 extend from the ends of the rear and front wall panels 16and 20 and are provided with book portions 27 adapted to engage, andinterlock with, appropriately shaped locking cuts 28 in the side panels12 and 13. I

The blank A first undergoes a preliminary folding and gluing operation.Adhesive is applied to the glue lap 23 and the panels 21, 22, 23 arethen folded back upon panels 20, 11 to bring the glue lap 23 intoadhesive engagement with the bottom panel 11. It is readily apparentthat subsequent folding of the outer front wall panel 29 into uprightposition with respect to the bottom panel automatically results in theformation of a hollow double walled front wall structure.

FIG. 2 shows the assembled carton A after assembly, but prior to fillingand closing. Formation of the box in volves folding of the wall panelsinto upright position with respect to the bottom panel and insertion ofthe hook portions 27 of the lock tabs into the locking cuts in order tointerlock the four box corners. It is also readily seen that erection ofthe hollow front wall assembly involves folding of the stock at fourfold lines, whereas folding of the rear wall panel 16 into uprightposition involves folding of the board along only one fold line. If thefolding is accomplished by insertion of the blank between appropriatelyshaped curved folding elements of the forming die, there is danger ofdisplacing the blank towards the back, as a consequence of whichmalformation of the box may result, or the corner locks may fail toengage.

FIG. 3 illustrates certain portions of a box forming machine of theplunger and die type which are essential for an understanding of thisinvention. At the upper portion of the figure a blank magazine is shown,mounted on a transversely extending structural member 29 of the boxforming machine. A stack of blanks A rests edgewise on a pair ofsupporting rods 3% supported by a bracket31 secured to a horizontalbottom rail 32 of the magazine gate 33. Two lateral gate rails 34'and'35 extend outwardly from the bottom rail 32 and are joined by ahorizontal top rail 36 carrying a stack retaining plate or lip 37slightly overlapping the tuck tab 13 of the frontmost blank so as toprevent the blank from falling out of the gates. Similar stack retainingplates or lips 38 and 39 are secured to the lateral rails 34 and andoverlap the dust flaps 14' 15 slightly. Lateral blank aligning rods 40and 41 are supported on the magazine gate by brackets 42 and 43.

The magazine gate 33 is normally slightly inclined with respect to thevertical in the sense that its top rail 36 is slightly forward of thebottom rail 32, as is also indicated in FIGS. 4- and 5. The rods 30, 49and 41 locate the blanks accurately with respect to the magazine gateand to the remainder of the machine, so that a positively acting feedingmechanism with respect to which the blank is not permitted to shift willeliminate the need for subsequent realignment of a blank with respect tothe box forming mechanisms, more particularly the die 44 shown in thelower portion of FIG. 3.

In accordance with accepted practice, the blanks are withdrawn one at atime from the magazine gate, advanced to the die 44' and then forcedthrough the die by an appropriately constructed plunger which causes thebox corners to interlock in a manner well known in the art.

- inasmuch as the construction and the operation of the plunger are notessential to an understanding of the invention, the plunger is not shownin any of the drawings.

The feeding mechanism comprises a transverse feeder bar 45 moved by anappropriately constructed mechanism to travel back and forth between themagazine gate and the die along a somewhat complex tially three phases.

During a first phase a blank is withdrawn from the stack by a motionsubstantially parallel to itself. During this phase the danger ofsliding of the blank relatively to the cups exists, particularly itincreased resistance to withdrawal through the magazine gate isexperienced. Such resistance may exist at one or several of the blankretaining lips of the magazine gate, or as a result of slightinterlocking of the blanks in the stack at tabs, cuts, etc., or byreason of wax coated blanks adhering to one another. Sliding may alsoresult from great smoothness of'a highly finished, for example, glossyblank surface.

During the second phase of the motion the blank is moved along anarcuate path so as to bring it from the substantially vertical positionit occupied in the magazine into a substantially horizontal positionabove the die.

A third and final motion moves the blank parallel to itself into themouth ofthe die where it is released by the feeder which then returns tothe magazine gate to pick up the next blank.

During the return motion of the feeder the plunger moves the blankthrough the die and causes the corners of the box to be interlocked,whereafter the box is then ejected from the bottom of the die.

The geometry of the feeder mechanism is best explained by referring toFIGS. 4 and 5. The feeder bar 45 is secured to one arm 46 of a doublearmed lever 47 whose other arm '45 is forked to provide for sliding aswell as pivoting engagement with a roller 49. The roller 49 is mountedon a bell'crank 50 pivotally mounted on the machine about a pivot 51.The bell crank further carries a link pin 52 from which a connecting rod53 extends to a link pin 54 of a main lever 55. The main motion havingessenlever is pivotally mounted on the machine about a pivot 56 andsupports the double armed lever 47 about a supporting pivot 57. Anactuating rod 58 leading to an oscillating arm, or a crank, of themachine mechanism (not shown) swings the main lever through an arc ofapproximately degrees from the position shown in FIG. 4 into theposition shown in FIG. 5.

The described feeder mechanism and particulars of the path traversed bythe feeder bar is described in considerable detail in the prior patentof Lefief, No. 2,805,06i), dated September 3, 1957.

The portion of the feeder which grasps the box blank is shown in greaterdetail in FIG. 7. The feeder head is mounted on the feeder bar 45 andcomprises a mounting plate 59 to which two projectible and retractablevacuum cup devices dti are secured at 61. Themouths 62 of the devices 60extend through holes53 in a plate 64 which, in the illustrated form offeeder head, constitutes a box blank supporting member adapted to guidethe folding of the blank along certain fold lines.

A screw 65 provided with a sharp point 66 extends through the plate 64and is held by a lock nut 67 in its properly adjusted position in whichthe point 66 projects below the bottom surface of the plate 64. Thebottom plate 64 is spaced from the mounting plate 59 by a block 68. Thefeeder head assembly is secured to the transverse bar by bolts 69,clamping plates 70 and nuts 71.

L-fittings 72 and vacuum lines 73 lead to a control valve 74 (FIGS. 4and 5) Whose valve member 75 in the position shown in FIG. 4 establishescommunication with a vacuum line 76 leading to a pump (not shown) and inthe position shown in FIG. 5 vents the line 73 to the atmosphere througha vent port 77. The dash dot line 78 indicates connection of the valvemember with an element oscillating through an arc of 90 degrees duringoperation of the machine. In the position shown in FIG. 4 the valve 74applies vacuum to the cups in order to pick up a blank, and in theposition shown in FIG. 5 the cups are vented to release the blank.

The vacuum cups 62 proper areprovided with servos means for projectingand retracting them. A particularly simple and preferred form of servomechanism is shown in FIG. 6.

The vacuum cup 62 is mounted on a metal bushing 79 having a bottomflange 84}. A second cup 81 is mounted on the bushing 79 and faces inthe opposite direction. The cup 8-1 is held in place by a top flange 82of the bushing 79. The bushing 79 is slid-able on a hollow central stem83 having an enlarged head 84 hearing against an internal shoulder 85 onthe head 84, thereby limiting the forward movement of the cup 62.

The threaded end 86 of the stem 83 is screwed into a hollow nipple 87 onwhich a further cup 88 is seated between flanges 89 and 90 and lies faceto face with the rim of the cup 81. A chamber 91 is thus formed by cups81 and 88 communicating with the interior of the nipple 87 through ahole 92 in the nipple 87, the nipple being in communication with the L72 and the vacuum line 73.

When a blank attaches itself to the cup 62, the pressure inside the cupchamber 91 drops and the cups 81, 88 collapse to a certain degreethereby retracting the blank grasping cup 62. The movement of the cup 62is guided by the bushing 79 sliding on the stem 83. The retractingmotion continues until the top flange 82 of the bushing 79 strikes theflange 89 of the nipple.

The cups 62, 81 and 88 may be made of natural or synthetic rubber. Theresiliency of the cup material causes the cups to return to the normalextended position, when the pressure inside the chamber 91 is made equalto the surrounding atmospheric pressure by venting the line 73 at thevalve 74.

FIG. 9 shows the feeder head at the moment of entry of the blank intothe folding die 44'. The vacuum cups 62 draw the blank flat against thebottom of the plate 64 except at the point 66 of the pin 65 where theblank bulges out slightly. The point 66 digging into the surface of theblank prevents shifting of the blank parallel to itself when the blankenters the die. It is readily seen that a tendency to shift to the rightexists, due to the greater resistance of the blank to folding at theleft where four fold lines are involved than at the right where theblank is only folded at one fold line.

The bottom edges of the plate 64 control the folding by supporting theblank up to the crease lines along which the blank is to fold.

In FIG. 8 a modified form of feeder head is shown in which the blanksupporting plate 164 is fitted with folding rules on edges 93 and acentral supporting surface 94 through which points 66 project.

FIG. shows a preferred form of feeder arm adapted to be mounted on thetransverse feeder bar. The arm 95 is offset at 96 and carries theretractable vacuum cup assembly 6G, 62. A screw 65 pointed at 66 extendsthrough soonest.

6 the offset and is readily adjustable in length with respect to the cupassembly. The point 66 digs into the blank surface and prevents not onlyshift-ing but also turning of the blank with respect to the vacuum cup62 in the event only one cup is used, as may be desirable in handlingsmall blanks.

What is claimed is:

1. A folding box blank handling device comprising, in combination, amagazine; a folding die means; a carrier; means for moving the carrierback and forth to pick up a blank at said magazine and deposit saidblank at Said folding die means; a suction cup mounted on said carrier,said cup having a blank grasping mouth and being retractible uponapplication of vacuum thereto; means for periodically applying vacuum tosaid cup; and a sharp pointed blank engaging element mounted on saidcarrier in a position in which the sharp point lies behind the plane ofthe mouth of the extended cup, but in front of the plane of the mouth ofthe retracted cup, so as to force the point into the surface of theblank held by the retracted cup and fix the blank against lateraldisplacement.

2. A pneumatic feeder head for box blanks comprising, a supportingmember adapted to engage and support the box blank adjacentpredetermined fold line-s preparatory to folding of the blank at saidfold lines by forcible insertion of the blank into a die device; asuction cup having a blank grasping mouth and being mounted in aposition in which the mouth is in advance of the said member; means forretracting the cup into a position in which the mouth is retracted atleast to a position flush with said member; and a sharp pointed blankengaging element mounted in a position in which its point lies behindthe plane of the mouth of the extended cup, but in front of the plane ofthe retracted cup, so as to force the point into the surface of theblank held by the retracted cup to fix the blank against lateraldisplacement.

3. A. pneumatic feeder head for box blanks comprising, a supportingmember adapted to engage and back up the box blank adjacent certain foldlines preparatory to folding the blank at said fold lines by forcibleinsertion of the blank into a die device; a pair of suction cups, eachcup having a blank grasping mouth and being mounted in a position inwhich the mouth is in advance of said member; means for retracting saidcups into a position in which the mouth is retracted at least to aposition flush with said member; and a sharp pointed blank engagingelement mounted between said cups in a position in which its point liesbehind the plane of the mouth of the extended cups but in front of theplane of the mouth of the retracted cups, so as to force the point intothe surface of the blank held by the retracted cups to fix the blankagainst lateral displacement.

4. In a folding box blank shaping assembly comprising a die device, thecombination of a blank supporting member adapted to engage and back upthe box blank adjacent certain fold lines preparatory to folding theblank at said fold lines by forcible insertion of the blank into a diedevice by said head; a suction cup having a blank grasping month, saidcup being mounted on said member in a position in which the mouth liesin advance of said member; means for applying vacuum to said cup; asharp pointed blank engaging element mounted in a position in which itspoint lies behind the plane of the mouth; and means responsive to thepresence of vacuum at said cup for retracting said cup mouth into aposition behind said point, whereby the point is forced into the surfaceof the blank held by the mouth to prevent shifting of the blankrelatively to said member.

5. A mechanism for feeding and prefolding box blanks, the mechanismcomprising a die device; a blank supporting member adapted to engage andback up a box blank overlying the member adjacent certain fold linespreparatory to folding the blank at said fold lines by forcibleinsertion of the blank by said member into the die device; a pair ofsuction cups, each cup having a blank grasping a '3 mouth and beingmounted in a position in which the mouth lies in advance of said member;means for periodically applying vacuum to said cups; a sharp pointedblankengaging element mounted in a positionin which the point'liesbehind the plane of the mouth, but in advance of the blank engagingplane of said member; means responsive to the presence of vacuum at saidcups for retracting said cups into a position in which their mouths liebehind said point to force the point into the surface of a blank held bysaid cups; and means for periodically reciprocating said member withrespect to said die device.

6. A folding box blank feeding device comprising, in

combination, a carrier; means for moving the carrier back and forthbetween a first blank pick-up station and a second blank depositstation; a pair of suction cups mounted on said carrier, each cup havinga blank grasping mouth and being contractible upon application of vacuumthereto; means timed with said back and forth motion for periodicallyapplying vacuum to said cups; and a sharp pointed blank engagingelement'mounted on said carrier in a position in which the sharp pointlies behind the plane of the mouths of the extended but in 8 front ofthe plane of the mouths of the contracted cups, so as to force the pointinto the surface of the blank upon application of vacuum.

7. A folding box blank feeding device comprising, in combination, acarrier; means for moving the carrier back and forth between a firstblank pick up station and a second blank deposit station; a suction cupelement mounted on said carrier and having a blank grasping mouth; meansfor periodically applying vacuum to said cup element; a sharp pointedblank engaging element mounted on said carrier; and means forperiodically adjusting the relative position of said elements from oneposition in which the mouth lies in advance of said point into a secondposition in which the mouth lies behind said point.

in which second position the point is forced into engagement with thesurface of a cupheld blank.

References Cited in the file of this patent UNITED STATES PATENTS2,406,766 Harrold n Sept. 3, 1946 2,805,060 Lefief Sept. 3, 1957

